The left-hand file is the U 87, the right-hand file is its MJE C1 pairing. In all cases, the recordings were made with both mics live, mics positioned vertically in headbasket-to-headbasket orientation. Vocal distance apx 10", guitar distance apx 18".
This is Michael Joly writing. Listen and read more to learn if an MJE modification for your SP C1 is right for you. Then place an order or click "contact me" to send your questions.

Btw - The '70's U 87 heard below (about $3000 used) uses the Neumann K67 capsule followed by HF de-emphasis in a FET / transformer-coupled circuit. As a FET / tranformerless mic, the MJE SP C1 is not a U 87 clone. Rather, I have chosen this classic '70's vintage U 87 as reference standard to showcase the qualities of the Michael Joly Engineering modification of the Studio Projects C1.

Q: Is this a complete, mod'd mic I'm buying?
A: NO. THIS IS A MODIFICATION SERVICE TO A MIC YOU SUPPLY. The picture shows a typical Studio Projects C1 supplied to us by a client, after it has been modified.